The invention relates to insulation for exterior walls, in particular, low-cost insulation using readily available materials which can be assembled on-site. Much of the prior art pertains to factory made articles which are not assembled on-site from readily available materials.
Materials such as pumice have high insulation values and are locally available in some areas such as the southwest United States. Use of such materials to insulate exterior walls provides a means for low income individuals to insulate their houses at minimal cost. Stacking bags of the insulation material against the exterior wall enables the insulating structure to conform to uneven wall and ground surfaces. Insulation members such as those described in U.S. Pat. No. 3,979,870 utilize low cost insulation materials but are not readily assembled on-site and are rigid and thus do not comform to uneven surfaces.